LeConte.l 



TOMICINI. 857 



XYLOTERUS Er. 



In this genus the club of the antennae is oval, compressed and solid, 

 without articulations ; the basal shining corneous part extends forwards in 

 a narrow band as far as the middle, except in X politus, where it is entirely 

 basal, and the club is indistinctly divided by one round suture ; the rest of 

 the surface is opaque, finely pubescent and sensitive. The funicle is com- 

 posed of two parts, as in the two preceding genera ; the first joint is large, 

 and stout as usual, the remaining part is about equal in length, forming 

 a pedicel to the club, and is divided by two not well marked transverse 

 sutures, thus causing the funicle to be 4-jointed. The eyes are moderately 

 finely granulated and completely divided. Tiie head is large, exserted, 

 and in the (^ is deeply concave. The prothorax is broader than long, and 

 strongly asperate in front in the 9, less so in the (^. The tibiae are 

 dilated, finely serrate on the outer edge, rounded at tip, and very feebly 

 mucronate at the inner angle ; the tarsi have the joints 1-3 rather stout, 

 nearly equal in length ; fourth very small, fifth slender, as long as the 

 second and third united, with simple divergent claws. The hairs are not 

 serrate or verticillate, as in Pityophthorm, but slender and smooth. 



The four species in our fauna are easily recognized: 

 Elytra with well defined strife of punctures, interspaces 



nearly smooth 2 . 



Elytra with ill-defined distant rows of punctures, inter- 

 spaces equally strongly punctured, pubescence 



erect, abundant 4. politus. 



2. Prothorax finely and sparselj"^ punctured at the sides 



towards the base 1. retusus. 



Prothorax finely but less sparsely punctured at the 



sides towards the base 2. bivittatus. 



Prothorax scabrous and granulate behind the middle 3. scabricollis. 



1. X. retusus Lee, Trans. Am. Ent. Soc. 1868, 158. 



Canada one (J'. It is quite possible that this is only an extraordinarily de- 

 veloped specimen of the next, but as I have seen no intermediate forms, I 

 would suggest that for the present, it be retained as a distinct species. It is 

 of larger size, (4.5 mm.; .18 inch), rather stouter, with the prothorax more 

 suddenly declivous, and distinctly retuse in front, and less punctured on the 

 sides behind the middle. Otherwise the differences are chiefly in color, 

 which is of no value in this genus. 



2. X. bivittatus Manuh., Bull. Mosc. 1858, 236; Apalebic. Kirby, Faun- 

 Bor. Am. iv, 192, pi. 8, f. 5; Bostrichuit caoifrom Mannh., Bull. Mosc. 

 1843, 297 (c^); ibid. 1852, 359; Xyloterus cav. Mannh., ibid. 1852, 385. ./. 



Maine, Canada, Alaska, Vancouver Island. Length 3-3.3 mm.; .12-13 

 inch. Varies greatly in color. Usually the front part of the prothorax, the 

 suture and the margin of the elytra are black; sometimes only a short, ])ale 

 s'ripe is seen on e uh elytron. 



